One of the options venues are going to offer you to upgrade is the linen. Usually venues supply a regular white floor length poly linen. Poly is the basic linen and they usually will put a white poly over lay on as well. You have a lot of different options when upgrading linens. You can choose a table runner, overlay or a full length linen. Prices will range from $20 - $100 ++ per linen.
A couple of linen rental sites where you can peek at options are:
A nice satin or shantung linen is not that expensive and it adds a nice shine to the table. You can also upgrade your napkins as well. This is where a nice pop of color comes in. If you don't have the budget to upgrade linen, adding that napkin is a cheaper alternative usually $1 - $3 per napkin. Check out some photos below.